In general, a compressor that is used in the air-conditioning system for a vehicle sucks a coolant, which has evaporated through an evaporator, changes into the coolant at high temperature and high pressure for easy liquefaction, and then sends it to a condenser.
Such a compressor is operated in a way of compressing a coolant using power from the engine of a vehicle and a way of compressing a coolant through a compression unit using torque from a driving unit such as a driving motor operated by separate power.
In general, an electric compressor that compresses a coolant using torque from a driving unit operated by separate power includes a driving unit, which includes a driving motor in a compressor housing, and a compression unit that compresses a coolant. The driving motor of the driving unit is controlled by an inverter at a side in the compressor housing, and accordingly, the RPM of the driving motor is controlled and cooling efficiency can be variably controlled.
However, the cover on a side of the inverter of electric compressors of the related art is a thin plate, so the strength is low. Further, since the cover is a thin plate and the strength is low, the cover is easily damaged or broken even by small shock, so the time and cost for maintaining the electric compressors are increased.
Further, according to the electric compressors of the related art, when they are operated, vibration and noise are generated by rotation of the driving unit and operation of the compression unit, and the vibration and noise generated in the compressor housing are transmitted to the cover, so they decrease fatigue strength of the cover, and if severe, they damage the cover.
Further, according to the electric compressors of the related art, when they are operated, resonance sound in a specific frequency band is generated by the vibration and noise transmitted from the compression housing, so the vibration and noise are amplified and interfere with riding comfort for a driver or passengers.